We will study 40 patients with symptomatic DVT or PE confirmed by ultrasound or chest computed tomography respectively and treat them with once daily enoxaparin as a bridge to warfarin. In this case-control series, we will match 2 historical controls by age and gender to every case. Controls who received twice daily enoxaparin as a "bridge" to warfarin for acute venous thromboembolism will be matched from a retrospective study of previously hospitalized patients. Additional characteristics of matched control group will include: prior DVT or PE, cancer, heart disease, and pulmonary disease.